DataIncludes: Definitions, ExampleData are observations or facts that can become information or knowledge

IndexIncludes: Definition:, What do indexes tell you?, How can we calculate an Index?, When is an index not appropriate?An Index is a number used to show the variation in some quantity over time.

MeanIncludes: Definition , Here's another way of looking at it!, How do you calculate the mean?, When is the Mean not a useful measure?The mean is a summary number that measures the midpoint of a dataset.

Measures of Error and SpreadIncludes: Definitions, Calculations, Using Standard Deviation, Standard Error and Relative Standard ErrorStandard deviation measures the scatter in a group of observations

MedianIncludes: Definition, What can the Median tell you?, How do you calculate a Median?, When is the Median not a good measure of central tendency?The median is the middle score that seperates the lower half of a dataset from the higher half.

ModeIncludes: Definition , What does the mode tell you?, How do you calculate a mode?, When is the mode not a good measure of central tendency?The mode is the most commonly observed data item in the data set

PercentageIncludes: Definition, What does Percentage tell you?, How do you calculate the Percentage?, Benefits and downfalls of PercentagePercentage is a term used to express a number as a fraction of 100.

Population, Sample and EstimateIncludes: Definitions, What do populations and samples tell us?, Which to use in a survey - Population or Sample?A population is any entire group with at least one common characteristic.

ProbabilityIncludes: Definition, What can Probability tell you?, How do you calculate Probability?, Benefits and downfalls of ProbabilityProbability refers to the liklihood (or chance) of an event occuring.

Quantitative and QualitativeIncludes: Definitions, ExampleQualitative data describes an objects attributes that cannot be measured with numbers. Quantitative data is data characterised by numbers.

RangeIncludes: Definition, What does the Range tell you?, How is the Range calculated?, Benefits and downfalls of using the RangeRange represents the distance between the highest and lowest values of a data set.

RateIncludes: Definition:, What does Rate tell you?, How is the Rate calculated?Rate is an expression of ratio; it represents the relationship between two numbers.

RatioIncludes: Definition, What does Ratio tell you?, How do you calculate the Ratio?Ratio is a way of concisely showing the relationship of one quality relative to another.

Time SeriesIncludes: Definition- Time series, Why are Time-series Created?, Definition- Seasonally Adjusted Time-series, Why are Time-series Seasonally Adjusted?, Definition- Trend Time-series, Why are Trend Time-series Created?, Take care when using Time seriesA time series is a collection of observations obtained through repeated measurements through time.